1. Field of the Invention
The present invention relates to a magnetically guiding system and a magnetically guiding method for magnetically guiding a medical device that is introduced into the body of a test subject.
2. Description of the Related Art
In the field of endoscopes, there have been capsule medical devices having image capturing functions and radio communication functions. A capsule medical device is introduced into the body of a test subject such as a patient via the oral route, to check the inside of an internal organ of the test subject. The capsule medical device inside the body of the test subject sequentially captures images of the inside of the internal organ (hereinafter also referred to as in-vivo images) at predetermined intervals, while moving in the internal organ through peristaltic movement. The capsule medical device then sequentially radio-transmits the in-vivo images to the outside. The capsule medical device inside the body of the test subject sequentially repeats the capture and radio transmission of the in-vivo images until it is excreted from the body of the test subject. In the end, the capsule medical device is excreted from the body of the test subject.
Each of the in-vivo images captured by the capsule medical device is received by a receiving device outside the body of the test subject, and is input to an image display device via the receiving device. The image display device displays each of the in-vivo images on its display screen. A user such as a medical doctor or a nurse observes the inside of the internal organ of the test subject through each of the in-vivo images displayed on the image display device. Based on the observation result, the user can make a diagnosis on the test subject.
In recent years, systems that magnetically guide a capsule medical device inside the body of a test subject have been proposed. As an example of such a magnetically guiding system, there is a system that magnetically guides a video capsule inside a human body located in an operating space surrounded by fourteen individual coils (see Japanese Patent Application Laid-open No. 2005-81147).
In a medical device guiding system disclosed in Japanese Patent Application Laid-open No. 2004-255174, a capsule medical device that has an image capturing function and a magnet enclosed inside a capsule-like casing is introduced into a digestive tract of a test subject, and a rotating magnetic field is applied to the capsule medical device inside the body of the test subject, so as to magnetically guide the capsule medical device to a desired position inside the body of the test subject. In this case, the capsule medical device inside the body of the test subject moves, as the magnet inside the capsule-like casing follows the rotating magnetic field applied from the outside.